Motor Controllers

[philso]

Originally Posted by Ari423

Can you not just crimp or solder them (cue debate on crimping vs soldering)?

We used the 2-position "0.100" Latching Polarizing Connectors" from Hansen Hobbies for the CAN wires on the Talon SRX's last year and had zero problems throughout the competition season plus the 3 or 4 off-season events. The pins can be crimped with the same crimper used for the normal PWM cables. We also crimped Anderson connectors onto the input and output wires so that the whole motor controller can be swapped out quickly and easily (did not have to) or it can be re-used as is. Just be sure to do a pull-test immediately after each and every crimp and to have someone else inspect the work (and repeat the pull-test) to ensure it was all done correctly. We coiled up the excess wire and tied it up neatly using small cable ties. The connectors for the CAN connections were contained within the loop, guaranteeing that no physical strain is put on the connection.

http://hansenhobbies.com/products/co...nlpconnectors/
http://hansenhobbies.com/products/co.../pt1in_lp_1x2/

[MrForbes]

Originally Posted by philso

We also crimped Anderson connectors onto the input and output wires so that the whole motor controller can be swapped out quickly and easily (did not have to) or it can be re-used as is

I wonder if the 2016 FRC rules will consider this a "FABRICATED ITEM" and disallow it's use, if it was terminated before kickoff?

So many fun things to consider....

[FrankJ]

Originally Posted by MrForbes

I wonder if the 2016 FRC rules will consider this a "FABRICATED ITEM" and disallow it's use, if it was terminated before kickoff?

The 2015 rules has a specific exception for wiring terminations to COTs devices. I would think the 2016 rules would have the same exception. We will see. As a robot inspector, this is not an area I would focus on unless told to anyway.

[philso]

Originally Posted by MrForbes

I wonder if the 2016 FRC rules will consider this a "FABRICATED ITEM" and disallow it's use, if it was terminated before kickoff?

So many fun things to consider....

It is always a risk when "future proofing" something. What you may have done one year may not be legal the next. At the very least, one can use these motor controllers on a practice robot with very little effort.

[FrankJ]

Talon SRX are my favorite. Unless you need the advanced features of the Talon the Victor SP makes more economic sense. I will wait to pass judgement on the new 2016 controllers when they prove their durability.

Other than size the jaguars don't deserve their bad reputation. We found them reliable when connected correct and not filled with metal shavings.

[GeeTwo]

Originally Posted by MrForbes

I wonder if the 2016 FRC rules will consider this a "FABRICATED ITEM" and disallow it's use, if it was terminated before kickoff?

So many fun things to consider....

It would have been allowed last year under R12c.

Originally Posted by 2015 Game Manual

R12 Physical ROBOT elements created before kickoff are not permitted. Exceptions are:

• A. OPERATOR CONSOLE,
• B. battery assemblies per R4,
• C. FABRICATED items consisting of one COTS electrical device (e.g. a motor or motor controller), connectors, and any materials used to secure and insulate those connectors

However, this exception was not included for the withholding allowance; if you wanted a pre-terminated controller as a spare part, it needed to be included in the withholding allowance.

Originally Posted by 2015 Game Manual

R17 At an Event, Teams may have access to a static set of FABRICATED ITEMS, not bagged per R14, known as the WITHHOLDING ALLOWANCE, that shall not exceed 30 lbs. to be used to repair and/or upgrade their ROBOT. The WITHHOLDING ALLOWANCE may only be brought into the Venue when the Team initially loads in at the Event. Items made at an Event do not count towards this weight limit.
For Teams attending 2-Day Events, these FABRICATED ITEMS may be used during the Robot Access Period and/or brought to the Event, but the total weight may not exceed 30 lbs. FABRICATED ITEMS constructed during the Robot Access Period and bagged with the ROBOT are exempt from this limit.
Items exempt from this limit are:

• A. the OPERATOR CONSOLE,
• B. any ROBOT battery assemblies (as described in R4).

[GreyingJay]

Originally Posted by GeeTwo

However, this exception was not included for the withholding allowance; if you wanted a pre-terminated controller as a spare part, it needed to be included in the withholding allowance.

I wonder why they made that distinction. Is it too much of an advantage to have a drop-in replacement motor or controller ready to go?

I could see the first task for a student in the pit being to crimp some connectors onto a set of spare motors and controllers, ready to go.

In fact... *writes that down*

As for the poll, I voted for Talon SRX since it seems to offer quite a lot of potential advantages for the fairly minimal extra cost. Virtually every one of our robot failures last year, both on our practice field and unfortunately during our first regional, was some combination of our software addressing the incorrect PWM or DIO, the encoder wired incorrectly, read incorrectly, software values set/reset incorrectly, motors trying to run the forklift past the edge (e.g. we didn't have time to wire in a hard limit switch), etc. If we thought to use the limit switch and encoder functionality in the Talon SRX, and communicate over CAN instead of PWMs and DIOs, our code (and failure modes) could have been much simpler.